In recent years, chemical color development using pigment substances has become unacceptable in view of recycling properties and environmental protection. Under such circumstances, a structural color which develops a color utilizing a phenomenon such as diffraction and interference of light by forming a fine structure has come to be an important technique replacing the chemical color development.
A structural color is generated, for example, by thin film interference, multilayer interference, light scattering phenomenon, diffraction lattice and photonic crystals.
It is difficult to cause such a structural color to be developed artificially. There are very few cases where structural colors are developed on the industrial scale.
As one of these few cases, a method has been proposed in which a fine periodic structure is formed by light irradiation, thereby developing a structural color.
As examples of the fine periodic structure formed by light irradiation, LIPS (Laser Induced Periodic Structures) (see Non-Patent Document 1, for example) can be given, for example. The LIPS are fine periodic structures which are formed by laser irradiation on the surface of a material in a self-organized manner.
As another example, a technology is disclosed in which a diffraction lattice is formed in the inside of glass by means of a femtosecond laser (see Non-Patent Document 2, for example).    Non-Patent Document 1: Sylvain Lazare: “Large scale excimer laser production of submicron periodic structures on polymer surface” Applied Surface Science 69 (1993) 31-37, North-Holland    Non-Patent Document 2: Journal of Japanese Society of Laser Technology, Vol. 30, issue 2, Hideo Hosono and Kenichi Kawamura, “Interaction between Femtosecond Laser and Transparent Substance Decoration of a Transparent Substance with a Periodic Nanostructure by a Single Pulse Interference”, Japanese Society of Laser Technology, May 2005, pages 7-12.